Oil well tubing cleaners



April 1961 R. L. WINEGAR 2,979,133

on. WELL TUBING CLEANERS Filed Aug. 20, 1957 IN VEN TOR.

L v RoBERT Lee WINEGAR BY PM HUT: I $71-84 L ATTORNEYS.

- the attachment of the blade :to the sucker rod,

2,979,133 H. WELL TUBHIG CLEANERS Robert Lee Winegar, Borger, Ten,assignor to J. M. Huber Corporation, Borger, Ten, a corporation of NewJersey Filed Aug. 20, 1957, Ser. No. 679,265

2 Claims. (Cl. 166-176) This invention relates to tubing cleaners forpreventing and removing accumulations of paraffin and other substanceswhich tend to clog the tubing of an oil well and thereby restrict theflow of oil therethrough.

The oil well tubing cleaners heretofore provided for this purpose haveall been deficient in various respects. Some of them have used scraperblades of spring steel mounted by spring tension upon sucker rods; butin these cases the spring steel blade often does not grip the sucker rodsufficiently and tends to creep along the rod during the well pumpingoperation. In some cases a flat scraper blade lying in a plane parallelto the axis of a sucker rod is secured to the rod by U bolts whichembrace the rod, but such U bolts tend to loosen during operation sothat the blade not only can move along the sucker rod but sometimesbecomes detached and falls to the bottom of the well.

Scraper blades have been fastened securely to sucker rods by providinglong blades secured by U-shaped bands or clamps which embrace the suckerrod and are welded at their ends to the scraper blade, with the bladelying tangentially against the cylindrical surface of the rod, so thatthe clamps grip the rod by shrinking as they cool after the weldingoperation. These long blades are clamped at two or more locations alongthe suckerrod in order to secure satisfactory rigidity, and the scraperblade thus acts as a very strong stiffening member along the portions ofthe sucker rod embraced by the U-shaped bands or clamps welded to theblade. During the welding the scraper blade and spaced portions of therod are heated intensely yet unevenly, and as the heated parts cool thesucker rod is placed under strains tending to cause bending of the rod.These strains lead to breaks of the sucker rods which occur just outsidethe bands well tubing cleaner comprises a substantially flat bladewhichlies in a plane parallel to the axis of the sucker 2,979,133 PatentedApr. 11, 1961 The above, and other objects, features and advantages ofthe invention, will be apparent in the following detailed description ofillustrative embodiments thereof which is to be read in connection withthe accompanying drawing, forming a part hereof, and wherein:

Fig. 1 is a front view of an oil well tubing cleaner embodying thepresent invention, and shown attached to a sucker rod;

Fig. 2 is a cross section through the blade and rod showing the clampand welding beads in end elevation; and

Fig. 3 is an end elevational view of the blade structure of Fig. 1.

Referring to the drawing in detail, and initially to Figs. 1 and 2thereof, it will be seen that an oil well tubing cleaner embodying thepresent invention, and there generally identified by the referencenumeral 10, includes a substantially flat scraper blade 11, a single,generally U-shaped band or clamp 12 which embraces the sucker rod 13,and welding beads 14 joining the opposite end edges of the band 12 tothe scraper blade 11.

The method employed in securing the oil well tubing :Cleaner 10 to thesucker rod 13 is'preferably that disclosed in United States LettersPatent No. 2,468,508 to R. C. Lister and, in accordance therewith, theinner curved surface of the band 12 is substantially semi-cy- The innerdepth A (Fig. 2) of the band '12, that is,

the distance from the inner surface of the semi-cylindricalportion ofthe band to the ends of the legs thereof,

measured in the direction parallel to the legs, is slightly less thanthe diameter d of therod 13 so that, when the band 12 is placed over therodl3 with the ends extending toward the scraping blade 11 and thelatter abutting rod and is secured to the latter by a single, generallyl U-shaped clamp embracing the sucker rod and having its opposite endedges welded to the blade in a way to grip the rod securely by shrinkageas the clamp cools, and the blade has a length along its outside orscraping edges, in the direction of the axis ofthe sucker rod, which isfrom one-half to one and one-half times the maximum dimension of theblade measured in the direction perpendicular to said axis, thereby tomake feasible the attachment of'the blade to the sucker rod by a singleclamp, while the clamp itself has a length in the direc-y,,f tion of theaxis of the sucker rod at least as large as the diameter of the rod andat least one-thirdthe length of any straight edge of the blade extendingparallel 'tolthe axis of the rod, in order torensuresuitable rig'tangentially against the surface of the rod 13, each end edge of theband lzwill be spaced a small distance from the surface of the bladeilto provide a clearance for the formation of the welding beads 14.Preferably, the clear- "ance for accommodating the welding heads is fromabout to about%4'of an inch, whichclearance has been i foundtoproducethe desired amount of clamping pres sure onthe rod 13 whilemaking it possible to form the necessary welding .beads..

An apparatus, as disclosed in the above identified patent to Lister, isemployed for exerting a substantial The welding beads Mare formed'eithersimultaneously orone immediately after theother, and-whenbo'th beads 1i4 navebeen formed they are quicklyrcooled by directing one or morestreams of cool fluid thereagainst, thereby to avoid the transfer ofheat to the sucker rod 13 which It is apparent that the time required'for the formation of the welding beads 14 isdep'endent,'to.a large.extent, upon the lengths of such beads, and will. determine the extentofthe heattransfer to-the sucker rodgl3. Lin accordance' with the,present. invention,;the, length lsi bf-the outside orscraping-edges' l5ofifthebladein [-ths'ep onection' of the axis' of the rod is limited toa i irnension which' isffrom One haIf tofone an'd. one half be less than2. inches or 3 inches, and the greatest dimension of the bladelengthwise of the sucker rod is less than 3 inches or 4 /2 inches, asthe case may be.

' It has been found that, in order to provide a suitably rigidattachment of the cleaner to the rod 13, the length l of the band 12 inthe direction of the axis must be at least as large as the diameter a?of the'sucker rod 13 and at least one-third the length of any straightside or edge of the blade 11 extending parallel to the axis of thesucker rod. In Fig.1, compare the length l with the length. L of thestraight, opposite side edge portions 15 of blade 11.

Although the length l of the band or clamp 12, should be at least aslarge as the diameter d of the rod 13 and at least one-third the lengthL of the straight edges 15 of the blade 11 extending parallel to theaxis of the sucker rod, to ensure adequate rigidity in the attachment ofthe oil well tubing cleaner to the sucker rod, and, in some cases, thelength of the U-shaped band or clamp may be substantially less than thelength of the blade, as in the embodiment of Figs. 1 and 2, it is to beunderstood that the maximum length of the U-shaped band or clamp inthedirection of the axis of the sucker rod is limited only by the length ofthe scraper blade in the same direction.

In accordance with the illustrated embodiment of the invention, agenerally flat scraper blade 11 is of uniform width W over only thelength L of the central portion thereof having straight, opposite sideedge portions 15 extending parallel to the axis of the sucker rod 13,while the opposite end portions 17 of the blade taper, or haveconverging side edges. 7

Further, as seen in Figs. 1 and 3, the! ends of the tapering endportions 17 of the scraper blade 11 are bent into arcuateconfigurations, as at 18 (Fig. 3), conforming to the surface of thesucker rod 13 and embracing the latter, thereby to contribute to therigidity of the attachment of the cleaner 10 to the sucker rod.

It will be apparent that, in each embodiment of the invention, thescraper blade is proportioned to permit its tached, for example,an'angular displacement as small as five degrees occurring at the bottomof the stroke of the sucker rod, permits the edges of the scraper bladeto cut a new open path through the deposit within the oil well tubingduring each upward and downward movement of the sucker rod. Actually,such limited angular displacement of the scraper blade results in moreeffective cleaning than relatively great angular displacement orrotation of the blade which may only cause the latter to cut grooves inthe deposit.

Various changes and modifications may be effected in the illustratedembodiments of the invention without departing from the scope or spiritof the invention defined in the appended claims. a

What is' claimed is: I r

1. An oil well tubing cleaner comprising a sucker rod, a generally flatsteel scraper blade predominantly lying at one side of said rod in aplane parallel to the axis of said rod, and a single rigid U-shapedclamp having its central portiontightly'fitted upon said rod from oneside of said rod with its legs embracing and extending to the oppositeside of said rod and there welded at their ends to said blade by weldingbeads covering substantially the full length of the end of each of saidlegs, said blade comprising a central portion formed at opposite sidesof said rod with opposite scraping edges substantially parallel to theaxis of said rod, and comprising tapering opposite end portions eachhaving opposite side edges sloped toward said rod from ends of saidparallel side edges, the end of at least one of said tapering endportions being cupped into an arcuate configuration embracing thesurface of said rod to enhance the rigidity of the blade, the length ofsaid blade at said scraping edges being from one-half to one andone-half times the greatest width of said blade, and the length of eachof said leg ends and welding beads being at least as great as thediameter of said rod, whereby said blade is permanently and rigidlyclamped upon said rod, Without recrystallization or uneven straining ofthe rod in the region of the welding beads, for movement withreciprocation and limited rotation of the rod to scrape deposits fromthe inside of oil well tubing.

'2. An oil well. tubing cleaner comprising a sucker rod,

a generally ,flat steel scraper blade predominantly lying I atone sideof; said rod in a plane substantially tangent to the surface of the rod,and a single rigid U-shaped clamp having its central portion tightlyfitted upon said rod from attachment to the sucker rod by a singleU-shaped band or clamp which is shrink welded to the blade and which hasa relatively limited length in the direction of the 'longitudinal axisof the sucker rod, to produce a suitably rigid attachment while avoidingthe use of relatively long welding beads which, during the formationthereof, would result in excessive heat transfer and consequentobjectionable straining or crystallization of the sucker rod.

By employing a single U-shaped band or clamp which embraces the suckerrod at the side of the latter opposite from the scraper blade, the oilwell tubing cleaners embodyingthis invention ensures the substantiallyuniform stifiening of the. sucker rod at the opposite sides found thatthe most effective cleaning or cutting action 7 of such blades is not adirect function of the rotation {of the sucker rod but is caused, almostentirely, by the cutting action of the edge of the, flat scraper bladeas it v reciprocates with the sucker rod within the oil welltubv ing.'An 'angular displacement fof the scraper blade ,j through onl'y..-a-few degrees at anypoint'alongthe recip rocating stroke of the; slclrer ro'd. to .;vvhich it is at,-

one side of said rod with its legs embracing and extending to theopposite side of said rod and there shrink-welded at their ends to saidblade by welding beads covering substantially the full length of the endof each of said legs, said blade comprising a central portion formed atopposite: sides of said'rod with straight outside edges substantiallyparallel to the axis of the rod, and compris ing tapering opposite endportions each having opposite side edges sloped toward said rod fromends of straight side edges, the end of each of said tapering endportions being bent into an arcuate configuration embracing the surfaceof said rod to enhance the'rigidity of the blade, the length o fjsaidblade along said outside edges being from one-half to one and one-halttimes the greatest widthtof said blade, and the length of each of saidleg ends and welding beads being at least as great as the diameter of,said rod, :whereby said blade and said clamp are permanently and rigidlyshrink-Welded upon said rod, without recrystallization'or unevenstraining of the rod in the region of the welding beads, for movementwith reciprocation and limited rotation of the rod to scrape depositsfrom the inside of the oil well tubing;

References Cited in the file of this patent "UNITED srArns PATENTS

